JPH0786660B2 - Radiation image information reader - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial field of application> The present invention is produced in accordance with radiation image information stored and recorded by irradiating the storage phosphor sheet on which radiation image information is stored and recorded with excitation light. The present invention relates to a radiation image information reading device that photoelectrically reads radiation image information by detecting stimulated emission light, and more specifically, enables reading and erasing with the same light source and downsizing the entire device. The present invention relates to a radiation image information reading device that can be used.

<Prior art and its problems> As a method of obtaining a radiographic image as an image, a so-called radiographic system using a combination of a radiographic film having an emulsion layer made of a silver salt photosensitive material and an intensifying screen has been conventionally used. ing. Recently, as an alternative to the radiographic system, a radiographic image conversion system using a stimulable phosphor has been attracting attention.

Here, the stimulable phosphor means radiation (X-ray, α-ray, β-ray,
gamma rays, electron beams, ultraviolet rays, etc.), some of the energy of this radiation is accumulated in the phosphor, and when this phosphor is irradiated with excitation light such as visible light, Refers to a phosphor that emits stimulated emission.

By using this stimulable phosphor, the radiation image information of a subject such as a human body is once transferred to a sheet having a layer composed of the stimulable phosphor (hereinafter referred to as "stimulable phosphor sheet" or simply "phosphor sheet"). Accumulate and record, scan this sheet with excitation light to cause stimulated emission, generate the stimulated emission light with an optical element, convert it into an electrical signal to obtain an image signal, process this image signal, and perform diagnostic appropriateness. A radiation image information recording / reproducing system for obtaining a radiation image of a good subject has been proposed (for example, JP-A-55-12429, JP-A-56-11395, and JP-A-55-11395).
-163472, 56-104645, 55-116340, etc.).

By the way, this system has a practical advantage that an image can be recorded over an extremely wide radiation exposure area as compared with a conventional radiographic system using a radiation film and an intensifying screen.

That is, in the stimulable phosphor, it has been recognized that the amount of emitted light that is stimulated and emitted by excitation after storage is proportional to the radiation exposure amount over an extremely wide range. Therefore, even if the radiation exposure amount changes considerably due to various imaging conditions, the light amount of the emitted light is read by the photoelectric conversion means and read by the photoelectric conversion means to be converted into an electric signal. By using the to output a visible image on a recording material such as a photographic light-sensitive material or a display device such as a CRT, it is possible to obtain a radiation image that is not affected by fluctuations in radiation exposure. Therefore, these visible images also have an extremely great effect that they become radiation images with excellent observation and interpretation suitability (diagnosis suitability).

In such a radiation image information reproducing system,
Since the stimulable phosphor sheet does not store image information, it is only for temporarily holding radiation image information to finally give an image to the recording medium as described above,
This stimulable phosphor sheet may be used repeatedly, and if it is used repeatedly in this way, it is extremely economical and convenient.

Therefore, the present applicant has filed Japanese Patent Application Laid-Open Nos. 59-192240 and 59-256130.
No. 59-220739, No. 60-232029, JP-A No. 62-919
No. 33 and No. 62-124549 use an image reading unit that uses a laser light source as a reading excitation light source and scans a stimulable phosphor sheet with laser light deflected by an optical deflector such as a galvanometer mirror or a polygon mirror. , A plurality of fluorescent lamps, xenon lamps, etc. are used as an erasing light source, and an erasing section for emitting the radiation energy remaining in the read stimulable phosphor sheet is provided, and the stimulable phosphor sheet is efficiently circulated. A reusable radiation image information reading device and a radiation image information recording / reading device are disclosed.

The radiation image information recording / reading device or reading device uses a light source different from the reading light source and the erasing light source, for example, a laser light source as the reading light source, and a fluorescent lamp or a xenon lamp as the erasing light source. Therefore, it is necessary to separately provide the reading unit and the erasing unit, and there is a problem that the radiation image information reading apparatus becomes large.

Further, in the radiation image information reading apparatus in which the reading unit and the erasing unit are separately provided, there is a need for a transporting unit for the stimulable phosphor sheet from the reading unit to the erasing unit, and the transporting mechanism is complicated. In addition to the above, there is a problem that the device configuration becomes complicated and large.

<Object of the Invention> An object of the present invention is to solve the above-mentioned problems of the prior art, linearly squeeze one light source, and linearly irradiate a stimulable phosphor sheet as an excitation light source for image reading. By irradiating the stimulable phosphor sheet over a wide range with the above light source and using it as a light source for erasing, the size of the entire device can be effectively reduced, and the internal mechanism can be simplified. It is an object of the present invention to provide a small-sized and easy-to-use radiographic image information reading apparatus that can reduce the cost of the apparatus.

<Brief Description of the Invention> The present invention relates to a light source for irradiating a stimulable phosphor sheet on which radiation image information is stored and recorded, and a light emitted from the light source is linearly applied to the stimulable phosphor sheet. Irradiation light switching means capable of selectively switching between an irradiation state and a wide irradiation state on the stimulable phosphor sheet after reading is completed,
The stimulable phosphor sheet is disposed so as to face at least the length of the linear irradiating portion so as to face the portion of the stimulable phosphor sheet irradiated with the linear irradiating light, and the stimulable phosphor sheet is irradiated by the linear irradiating light. From the stimulable phosphor sheet, a photoelectric reading unit that receives the stimulated emission light emitted according to the radiation image information and photoelectrically reads the light source, the irradiation light switching unit, and the photoelectric reading unit. A radiation image information reading device is provided which is provided with a moving means for relatively moving the radiation image information reading device.

The irradiation switching means has a slit on one side for linearly irradiating the stimulable phosphor sheet with light emitted from the light source, and on the other side, the stimulable phosphor sheet after completion of reading. It is preferable that the slit plate is rotatable so as to widely irradiate the stimulable phosphor sheet with the light in order to erase the remaining radiation image information.

The surface of the slit plate on the light source side is preferably a reflecting surface that reflects the excitation light emitted by the light source.

Further, it is preferable that the photoelectric reading means has a line sensor including a large number of solid-state photoelectric conversion elements.

Further, it is preferable that the moving means is a conveying means for the stimulable phosphor sheet.

Further, it is preferable that the moving means is a reciprocating moving means of a reading / erasing unit having the light source, the irradiation switching means and the photoelectric reading means.

<Specific Configuration of the Invention> The radiation image information reading apparatus according to the present invention will be described below in detail with reference to the preferred embodiments shown in the accompanying drawings.

1a and 1b are sectional views of an embodiment of the radiation image information reading apparatus of the present invention, and FIG. 2 is a partially enlarged perspective view of FIG. 1a.

A radiation image information reading apparatus (hereinafter, simply referred to as “reading apparatus”) 10 of the present embodiment includes a cassette holding unit 12, a reading / erasing unit 14, and a stimulable phosphor sheet conveying means (hereinafter, sheet conveying means) 16. .

The cassette holder 12 is a portion that detachably holds the cassette 20 that can accommodate the stimulable phosphor sheet 18. Reader
An opening 26 for inserting the cassette 20 is opened in the side portion 24 of the housing 22 of the 10, and a cassette support base 28 extending outward from the opening 26 of the side portion 24 is provided. A lid-closing mechanism (not shown) for opening the lid member 20b of the cassette 20 is provided inside the housing 22 near the opening 26, and the main body of the cassette 20 opened.
A phosphor sheet take-out roller 30 for taking in and out the phosphor sheet 18 is provided to and from the 20a. When the lid member 20b of the cassette 20 is opened, the take-out roller 30 moves from the first position shown by the broken line in FIG. 1a to the second position shown by the solid line in FIG. 1a and comes into contact with the phosphor sheet 18. When rotated, the phosphor sheet 18 is carried out from the cassette 20, and conversely, when the reading and erasing are completed, the phosphor sheet 18 is fed back and completely stored in the cassette 20. (Position indicated by)).

A transport roller 32 that transports the phosphor sheet 18 to the reading / erasing unit 14 is provided in front of the take-out roller 30.

In front of the carrying roller 32, a sheet carrying means 16 which is a moving means for the reading / erasing section 14 of the stimulable phosphor sheet is provided. The sheet conveying means 16 is composed of two rollers 34, 36 and an endless belt 38 stretched around these rollers, and conveys the phosphor sheet 18 in the sub-scanning or erasing manner. Here, the stretch length of the endless belt 38 is preferably longer than the length of the phosphor sheet 18.

A reading / erasing unit 14 is arranged above the sheet conveying unit 16. The reading / erasing unit 14 includes a light source 40, a slit plate 42 as irradiation light switching means for switching the light source 40 between a linear irradiation state for reading / scanning exposure and an open entire surface irradiation state for erasing, and a phosphor sheet 18. And a photoelectric reading unit 44 for photoelectrically reading the stimulated emission light generated by the linear irradiation of the light source 40 to the.

The light source 40 may be any one that emits excitation light that can be read and erased, but the slit plate 42 for reading the excitation light.
The slit 46 makes a linear light beam 48, and the phosphor sheet 18
Is linearly radiated and the excitation light is radiated openly for erasing. Therefore, as shown in FIG. 2, a long light source is preferable. Typical examples of such a light source 40 include a tungsten lamp, an yoso lamp, a xenon lamp, a mercury lamp, a sodium lamp, and a fluorescent lamp.

The slit plate 42 is a rotatable semicircular tubular member, and the excitation light is made into a linear light beam 48 in order to linearly irradiate the phosphor sheet 18 with the excitation light emitted from the light source 40 on one side. The slit 46 is provided, and the other side is opened so as to directly irradiate the excitation light in order to erase the radiation image information remaining on the phosphor sheet 18 after the reading by the excitation light. In reading, as shown in FIG. 1a, the slit plate 42 is rotated by a rotation driving means (not shown) so that the slit 46 is positioned between the light source 40 and the phosphor sheet 18, and the light emitted from the light source 40 is slit. A linear light beam 48 is formed by 46, and the linear light beam 48 linearly irradiates the phosphor sheet 18 at a substantially right angle to cause stimulated emission according to the radiation image information carried by the phosphor sheet 18.

On the other hand, in erasing, as shown in Fig. 1b, the slit plate
42 rotates, open end of slit plate 42 (opposite side of slit)
Is directed toward the phosphor sheet 18 side, and the excitation light of the light source 40 is directly irradiated to the entire surface. Therefore, it is preferable that the inner side surface 50 of the slit plate 46 be a light reflecting surface so that the phosphor sheet 18 can be irradiated with all of the excitation light emitted from the light source 40. In addition, the inner surface 5 of the top member of the housing 22
2, it is preferable that the inner surface 54 of the portion covering the light source 40 is a light-shielding surface. Further, the inner surface 54 may be a reflecting surface.

The photoelectric reading unit 44 is arranged at least the length of the main scanning line 56 so that the linear light beam 48 that has passed through the slit 46 faces the main scanning line 56 defined on the stimulable phosphor sheet 18. From the phosphor sheet 18 to the phosphor sheet 18 by irradiation of the circular rays 48
A line sensor in which a large number of solid-state photoelectric conversion elements such as photoconductors, photodiodes or phototransistors that receive stimulated emission light generated according to the radiation image information carried by and are converted into electric signals are arranged in a substantially linear form. Have As the line sensor, for example, those disclosed in Japanese Patent Application Laid-Open Nos. 60-111568 and 60-230132 filed by the present applicant can be used.

The radiation image information reading apparatus of this embodiment is basically constructed as described above, and its specific operation will be described below.

In an external photographing device (not shown), the cassette 20 photographed on the phosphor sheet 18 housed inside is horizontally mounted as shown by an arrow B in FIG. 1a. Cassette 20
Is composed of a cassette body 20a and an openable / closable lid member 20b provided at the front end in the insertion direction into the cassette holding portion 12, and when loaded in the cassette holding portion 12, the lid member 20b is shown by a broken line in the figure. It is rotated from the closed position to the open position shown by the solid line in the figure. In the cassette holder 12, there is provided a take-out roller 30 which is a sheet take-out means for taking in and out the phosphor sheet 18 with respect to the cassette 20, and when the lid member 20b of the cassette 20 reaches the open position, the broken line in the figure Moves from the first position shown by to the second position shown by the solid line in the figure, and the phosphor sheet
The phosphor sheet 18 is rotated in contact with the sheet 18 and is carried out from the cassette 20.

The position of the tip of the phosphor sheet 18 housed in the cassette 20 loaded in the cassette holder 12 is the position P ₁ . The take-out roller 30 starts to carry out the phosphor sheet 18 from the cassette 20 by rotating in contact with the vicinity of the tip of the phosphor sheet 18 as described above, and delivers the phosphor sheet 18 to the conveying roller 32. The phosphor sheet 18 is carried into the reading / erasing unit 14 by the carrying roller 32 and the endless belt 38.

The phosphor sheet 18 is conveyed by the sheet conveying means 16 in the direction of arrow A _{1 as} shown in FIG. 1a, and when the other end reaches the scanning start position P ₂ which is the irradiation position of the linear light beam 48, Reading by irradiation of excitation light is started.

At this time, in the reading / erasing unit 14, the slit plate 42 rotates, the slit 46 is turned to the phosphor sheet 18 side to be in a reading state, and the excitation light emitted from the excitation light source 40 becomes a linear light beam 48 by the slit 46, and the phosphor sheet 18 is formed. Is irradiated linearly. By this linear irradiation of the excitation light, stimulated emission light is generated from the phosphor sheet 18 according to the radiation image information accumulated in the phosphor sheet 18. This photostimulated luminescence light is received by the photoelectric reading means 44, photoelectrically converted, and read as an electric signal. The read signal is signal-processed and stored in a memory or the like.

On the other hand, the phosphor sheet 18 from the insertion position tip position P ₁ of the cassette in the cassette holding portion 12 to the scanning start position P ₂
If the conveyance distance of is smaller than the length of the phosphor sheet 18 in the conveyance direction, the portion near the rear end of the phosphor sheet 18 remains in the cassette 20 when the front end of the phosphor sheet 18 is at the position P ₂ . Therefore, the reading of the phosphor sheet 18 is started before it is completely unloaded from the cassette 20, so that the transport distance of the phosphor sheet 18 can be shortened. By the way, prior to reading to obtain an image signal for visible image output (main reading), pre-reading is performed to read an outline of radiation image information accumulated and recorded in advance on a sheet, and the image information obtained by this pre-reading is read. There are cases in which the reading conditions and the like for performing the main reading are determined based on the above, and the main reading is performed according to the reading conditions (see, for example, Japanese Patent Laid-Open No. 58-67240).

When performing pre-reading together with such main reading, the phosphor sheet 18 is irradiated with the linear light beam 48 while the tip of the phosphor sheet 18 moves from the scanning start position P ₂ to the scanning end position P _{3 in the} arrow A ₂ direction. Is performed.

When the pre-reading is completed as described above, the endless belt 30
And the transport roller 32 is reversed by switchback,
The phosphor sheet 18 is conveyed in the direction of the arrow A ₃ and its tip is returned from the position P ₃ to the position P ₂ . When the front end of the phosphor sheet 18 is returned to the scanning start position P ₂ , the phosphor sheet 18 is conveyed again in the direction of the arrow A ₄ and the main reading is performed.

The main reading is performed while the front end of the phosphor sheet 18 is conveyed to the scanning end position P ₃ . In this way, the radiation image information carried on the phosphor sheet 18 is read over the entire surface.

When reading is completed, the slit plate is
42 rotates, the open end is directed to the phosphor sheet 18 side to be in an erased state, and the excitation light emitted from the excitation light source 40 is directly applied to the phosphor sheet 18 as erase light. At the same time, the endless belt 38 is reversed again, and the phosphor sheet 18 is conveyed in the direction of arrow A5 to be erased. When the erasing of the phosphor sheet 18 progresses, the phosphor sheet 18 is transferred to the transport roller 38, and the erasing is performed during this period. When the edge of the phosphor sheet 18 exceeds the scanning start position P ₂ , the erasing ends. After this,
The phosphor sheet 18 is further fed into the cassette 20 by the carrying roller 38, and the take-out roller 30 in the second position in the cassette 20 is in the opposite direction to the case where the phosphor sheet 18 is carried out of the cassette 20. Rotate and attach the phosphor sheet 18 to the cassette 20.
Bring it in completely. When the loading of the phosphor sheet 18 is completed, the take-out roller 30 returns to the first position again to prepare for the loading of the next cassette, the lid member 20b of the cassette 20 is returned to the closed position, and the cassette 20 is held in the cassette holder 12. Drawn from.

In the embodiment shown in FIGS. 1a, 1b and 2, the sheet conveying means 16 constitutes a conveying system by the rollers 34, 36 and the endless belt 38, and the phosphor sheet 18 is placed on the endless belt 38. The present invention is not limited to these, but the present invention is not limited to these, and as shown in FIG. 3, two pairs of rollers 60 and 62 are nipped and conveyed to perform scanning and erasing. You may.

The radiation image information reading device 11 shown in FIG. 3 has the same configuration as the reading device 10 shown in FIG. 1a except for the sheet conveying means 16, and therefore, the same components are given the same numbers and their explanations are omitted. .

As shown in FIG. 3, the sheet conveying means 16 has two pairs of rollers 60 and 62 and guide members 64 and 66 that sandwich and convey the phosphor sheet 18. The roller pairs 60 and 62 are synchronously driven by a driving means (not shown). The distance between the roller pairs 60 and 62 is preferably shorter than the length of the phosphor sheet 18 so that the phosphor sheet 18 is always nipped and conveyed by either one of the roller pairs. The guide members 64 and 66 are not necessarily provided as long as the phosphor sheet 18 is not curved between the roller pair, but it is preferable to provide the guide members 64 to favorably support the phosphor sheet 18. Further, the guide members 64 and 66 may be of any type as long as they can favorably support the phosphor sheet 18. Further, a guide member for suitably guiding the phosphor sheet 18 may be provided above the guide members 64, 66.

In the embodiment shown in FIGS. 1a to 3, the sheet conveying means 16 is constituted by a conveying system for the fluorescent sheet 18 and the fluorescent sheet 18 is used.
However, the present invention is not limited to this, and has a moving unit that moves the reading / erasing unit 14 relative to the phosphor sheet 18. All you have to do is to fix the phosphor sheet 18
The reading / erasing unit 14 may be movable so that the unit 14 is united. An example of this is shown in Figures 4a and 4b.

Radiation image information recording / reading apparatus shown in FIGS. 4a and 4b
Reference numeral 70 includes a radiation image information reading device 72 according to the present invention and a radiation source 76 such as an X-ray source arranged above an imaging table 74 which is an upper surface of the reading device 72. A stimulable phosphor sheet 78 is fixedly held on the lower surface of the table 74. The stimulable phosphor sheet 78 is a radiation transparent substrate 78a.
Further, the stimulable phosphor layer 78b is formed on the above, and the imaging table 74 also has a radiation transmissive property. The stimulable phosphor sheet 78 may be one in which a phosphor layer is directly formed on the lower surface of the imaging table 74. In this device, an image recording means is constituted by the radiation source 76 and the imaging stand 74.
80 are configured.

Below the above-mentioned phosphor sheet 78, a reading / erasing unit 84 in which the reading / erasing unit 14 is unitized and integrally housed in a housing 82 is provided, and is configured to be movable by a moving means. In this embodiment, a unit moving means 85 for reciprocating the reading / erasing unit 84 as a moving means.
The reading / erasing unit 84 is provided between the right end position (first position) shown by a solid line in FIG. 4a and the left end position (second position) shown by a solid line in FIG. 4b. It is possible to reciprocate while facing. In the present embodiment, the moving path in the direction of arrow C1 from the first position to the second position is the forward path, and the arrow from the second position to the first position is the arrow.
The return path is the travel path in the C2 direction.

The unit moving means 85, as shown in FIGS. 4a and 4b,
A screw rod 86 extending in the moving direction of the unit 84,
Unit support 88 that fits into this screw rod 86
And the gear 90 pivotally supported by the screw rod, and this gear
A gear 92 that meshes with the gear 90 and a motor 94 that rotates the gear 92 in both forward and reverse directions.
The unit support portion 90 is moved by rotating the screw rod 88 via the unit to reciprocate the unit 84.

When the subject 96 is placed on the imaging table 74 of the image recording means 80, the radiation source 76 is activated, the transmitted radiation image of the subject 96 is projected onto the phosphor sheet 78, and the radiation image information of the subject is the phosphor. It is stored and recorded in the phosphor layer 78b of the sheet 78.
When the photographing is completed, the reading / erasing unit 84 enters the image reading state shown in FIG. 4a, and the unit 84 reads the image information accumulated and recorded in the phosphor sheet 78.

Here, the reading / erasing unit 84 includes a light source 40, a rotatable slit plate 42, a photoelectric reading unit 44, a light shielding plate 98, and a housing 82 that integrally houses these, and is housed in the housing 82. Other than that, the configuration is the same as that of the reading / erasing unit 14 shown in FIG.

In the image reading state, the slit plate in the reading / erasing unit 84
42 is a light source 40 with the slit 46 side facing the phosphor sheet 78 side.
The phosphor sheet 78 is linearly irradiated with the excitation light of as a linear ray 48. From the linear irradiation location of the excitation light of the phosphor sheet 78, stimulated emission light is generated according to the image information stored and recorded, and this stimulated emission light is read by the photoelectric reading means 44 as an electric signal.

On the other hand, the reading / erasing unit 84 is conveyed by the unit moving means 85 at a constant speed in the direction of arrow C1 from the first position to the second position as shown in FIG. Read over.

When the reading is completed, as shown in FIG. 4b, the rotary slit plate 42 rotates approximately 180 °, the open end is directed to the phosphor sheet 78 side, and the excitation light of the light source 40 is directly irradiated to the phosphor sheet 18. . Here again, the reading and erasing unit 84 is conveyed in the erasing state from the second position to the first position in the direction of the arrow B, and the excitation light as the erasing light is irradiated over the entire surface of the phosphor sheet 78. . In this way, the radiation image information remaining on the phosphor sheet 78 after reading is almost erased,
Prepared for the next shoot.

In the example shown in FIGS. 4a and 4b, the phosphor sheet 78 is a fixed type, but may be removable.

In the examples shown in FIGS. 1a, 3 and 4a, the rotatable slit plate 42 was used as the irradiation light switching means, but the present invention is not limited to this, and FIGS. 5b
As shown, a slit plate 42 'that reciprocates in and out may be used, and as shown in FIGS. 6a and 6b, a liquid crystal shutter 42 "having a slit portion 46" may be used.

The embodiment shown in FIGS. 5a, 5b, 6a and 6b is the same as the embodiment shown in FIGS. 1a and 1b except for the irradiation light switching means, so that the same components are used. Are denoted by the same reference numerals, and description thereof will be omitted.

In the example shown in FIG. 5a and FIG. 5b, the lower surface of the housing 58 that houses the light source 40 is composed of a slit plate 42 ′ having a slit 46.

The slit plate 42 'can be reciprocated in and out by a driving means (not shown). Here, at the time of pre-reading and main reading, as shown in FIG. 5a, the slit plate 42 'is arranged on the lower surface of the housing 58, and the linear light beam 48 passing through the slit 46 linearly irradiates the stimulable phosphor sheet 18. To do.

On the other hand, when erasing, as shown in Fig. 5b, the slit plate 4
2'is moved laterally by a driving means (not shown), the lower surface of the housing 58 is opened, and the light source 40 irradiates the stimulable phosphor sheet 18 on the entire surface.

In the example shown in FIGS. 6a and 6b, the lower surface of the housing 58 that houses the light source 40 has a liquid crystal shutter 42 ″ having a slit 46 ″.
Composed of.

In this embodiment, as the liquid crystal shutter 42 ″, a known liquid crystal shutter is used which is a combination of a twist effect liquid crystal element using nematic liquid crystal and an optical polarizing plate. This liquid crystal shutter 42 ″ is shown in FIG. As shown in FIG. 8, it has a slit portion 46 ″ in its central portion, and as shown in FIG. 8, a nematic liquid crystal b is enclosed between two transparent glass plates a, a via spacers f, f, and both glass plates are sealed. a, a light polarizing plates c, c are arranged outside the transparent glass plates a, a, and transparent electrode layers d, d are vapor-deposited on the inner surface of the transparent glass plates a, a except for the slit portions 46 ″.
On d, d, organic film e, e provided with orientation performance in directions orthogonal to each other is provided. The both polarizing plates c, c are arranged so that the polarization directions thereof are orthogonal to each other.

The liquid crystal shutter 42 ″ constructed in this way has both electrode layers.
When a voltage V is applied to the liquid crystal b via d, d, the slit portion 4
Except for 6 ″, it becomes opaque and the whole becomes transparent when no voltage is applied. It is well known why the liquid crystal shutter 42 ″ changes the above state by applying or not applying voltage. Is omitted.

At the time of pre-reading and main reading, the liquid crystal shutter 42 ″
Is applied with a voltage V to the liquid crystal b through the electrode layers d, d shown in FIG. 8 and becomes an opaque state except for the slit portion 46 ″, so that it passes through the slit portion 46 ″ as shown in FIG. 6a. The linear light rays linearly irradiate the stimulable phosphor sheet 18. On the other hand, at the time of erasing, the voltage V is not applied to both electrode layers d, d in the liquid crystal shutter 42 ″, and the whole becomes transparent, so that the light source 40 entirely irradiates the stimulable phosphor sheet 18 as shown in FIG. 6b. To do.

Although the present invention has been described in detail above with reference to the preferred embodiments, the present invention is not limited to this, and as long as the reading light source and the erasing light source can be made the same, several sheets can be stored. The present invention can be applied to a large radiation image information reading device that circulates and uses a phosphor sheet to a small radiation image information reading device that uses a single phosphor sheet. It goes without saying that various improvements and design changes can be made within the range.

<Effects of the Invention> As described above in detail, according to the present invention, the reading of the radiation image information carried by the stimulable phosphor sheet and the erasing of the radiation image information remaining after the reading are performed by the same light source. Therefore, the reading device and the erasing device can be made compact.

Therefore, in the present invention, since the reading and the erasing can be performed in the same area, the transport distance of the phosphor sheet or the scanning moving distance of the reading and erasing section can be greatly reduced, and the radiation image information reading apparatus Cost reduction can be achieved by promoting miniaturization and compactness.

BRIEF DESCRIPTION OF THE DRAWINGS FIGS. 1a and 1b are schematic sectional views showing a reading state and an erasing state of an embodiment of a radiation image information reading apparatus according to the present invention, respectively. FIG. 2 is a partially enlarged perspective view of FIG. 1a. FIG. 3 is a schematic sectional view of another embodiment of the radiation image information reading apparatus according to the present invention. FIG. 4a and FIG. 4b are schematic cross-sectional views showing an outline of a reading state and an erasing state of one embodiment of the radiation image information recording / reading apparatus incorporating the radiation image information reading apparatus according to the present invention. 5a and 5b are schematic sectional views showing a reading state and an erasing state of another embodiment of the radiation image information reading apparatus according to the present invention. 6a and 6b are schematic cross-sectional views showing a reading state and an erasing state of another embodiment of the radiation image information reading apparatus according to the present invention. FIG. 7 is a perspective view of the liquid crystal shutter used in FIGS. 6a and 6b. FIG. 8 is a sectional view taken along line VIII-VIII in FIG. 7. Explanation of symbols 10, 11, 72 ... Radiation image information reading device, 12 ... Cassette holding section, 14 ... Read / erase section, 16 ... Accumulable phosphor sheet conveying means, 18, 78 ... Accumulable phosphor Sheet, 20 ... Cassette, 20a ... Cassette body, 20b ... Lid member, 22, 82
…… Case, 24 …… Side, 26 …… Opening, 28 …… Cassette support, 30 …… Eject roller, 32 …… Conveying rollers, 34,36…
… Roller, 38 …… Endless belt, 40 …… Light source, 42,
42 '... slit plate, 42 "... liquid crystal shutter, 44 ... photoelectric reading means, 46, 46' ... slit, 46" ... slit part, 48 ... linear light beam, 50 ... slit plate inner side surface , 52 ……
Inner surface of top member, 54 ... inner surface of light source section, 56 ... main scanning line,
60, 62 ... Roller pair, 64,66 ... Guide member, 70 ... Radiation image information recording / reading device, 74 ... Imaging stand, 76 ... Radiation source, 78a ... Substrate, 78b ... Storage phosphor Layer: 80 ... Image recording means, 84 ... Read / erase unit, 85 ... Unit moving means, 86 ... Screw rod, 88 ... Unit support, 90, 92 ... Gear, 94 ... Motor, 96 ... …subject,
98: light-shielding plate, a: transparent glass plate, b: nematic liquid crystal, c: optical polarizing plate, d: transparent electrode layer, e: organic film, f: spacer

Claims (1)

[Claims] 1. A light source for irradiating a stimulable phosphor sheet on which radiation image information is stored and recorded, a state of linearly irradiating the stimulable phosphor sheet with light emitted from the light source, and reading completion. Irradiation light switching means capable of selectively switching the state of wide irradiation on the stimulable phosphor sheet afterwards, and at least facing the portion of the stimulable phosphor sheet irradiated by the linear irradiation light, It is arranged at the length of this linear irradiation portion, and photoelectrically receives the stimulated emission light emitted from the stimulable phosphor sheet according to the radiation image information by the irradiation of the linear irradiation light. A radiation image information reading apparatus comprising: a photoelectric reading unit for reading, the light source, the irradiation light switching unit, and a moving unit for moving the photoelectric reading unit relative to the stimulable phosphor sheet.